1. Field of the Invention
The invention relates generally to fuel feed systems for internal combustion engines and more particularly to fuel feed systems including vapor separators.
2. Reference to the Prior Art
Because fuel used for internal combustion engines is aromatic, fuel vapor can easily evaporate from the fuel. When fuel in a fuel feed system for an internal combustion engine is under low pressure, excessive amounts of fuel vapor can form in the fuel feed system prior to introduction of the fuel to the internal combustion engine. In order to separate accumulated fuel vapor from the fuel supply prior to introduction of the fuel to the internal combustion engine, it is generally known in the prior art to place a fuel vapor separator in the fuel supply system.
Prior art designs of fuel vapor separators can include a float which is responsive to changes in the level of fuel in a chamber for opening and closing a valve to control removal of fuel vapor from the chamber. Such prior art designs often present difficulty, however, because once the float pushes the valve against its seat, further upward travel of the float is prevented. Subsequent slight disturbances in the float position, due to bouncing and fluid sloshing, cause unwanted, intermittent openings of the vapor outlet valve. This can lead to loss of liquid fuel through the vapor outlet. Also, the float can exert excess pressure on various components of the valve, for example, a valve member and a valve seat. Bouyant and inertial forces against the float can be excessive and can cause damage to the valve member and to the valve seat and/or to the float.
Attention is directed to the fuel vapor separators disclosed in the following U.S. Patents:
______________________________________ 4,534,774 LeCoffre et al. August 13, 1985 4,450,820 Haynes May 29, 1984 4,381,928 Roffelsen May 3, 1983 4,315,760 bij de Leij February 16, 1982 4,117,817 Nishida October 3, 1978 4,010,012 Griffin, III et al. March 1, 1977 3,985,626 Klein October 12, 1976 3,961,918 Johnson June 8, 1976 3,867,071 Hartley February 18, 1975 3,703,165 Hansen November 21, 1972 3,355,862 Blanchet et al. December 5, 1967 3,307,331 Lambert March 7, 1967 2,998,057 Graham August 29, 1961 2,917,110 Brohl December 15, 1959 2,878,889 Gilbert March 24, 1959 2,811,219 Wenzl October 29, 1957 2,745,551 Berck May 15, 1956 2,742,049 Granberg April 17, 1956 2,406,854 Samiran September 3, 1946 2,406,854 Samiran March 16, 1943 1,851,163 Daugherty March 29, 1932 1,804,557 Gould et al. May 12, 1931 1,381,897 Ackley June 21, 1921 1,119,980 Mulligan December 8, 1914 ______________________________________